what is this MBTI all about?
A fairly arbitrary way of pigeonholing people into personality types, based on the feelings of its creators back in the 50s who weren't trained psychologists and still marketed through the company they founded which definitely isn't a pyramid scam.
They market it increasingly in the developing world where it's still fresh and where people are more credulous.
It can be fun, in the way that astrology sun signs can be fun, however it's just a way of looking at things. The concept behind it is ideas from the twentieth century occult revival that have birth to the new age movement.
Mostly an American thing and not really taken seriously except by its hardcore fans, mostly female, less well educated and of 'spiritual' tastes.